6 ms·

If this destroyed the facility that would be the headline this news article.... WEST highest is 22 minutes (it's in the title) and you could google EAST and ITE

If this destroyed the facility that would be the headline this news article.... WEST highest is 22 minutes (it's in the title) and you could google EAST and ITER but the title tells you it is less than 22 minutes. WEST is a testing ground for ITER. The fact that you can have sustained fusion for only 22 minutes is the biggest problem since you need to boil water continuously because all power sources rely on taking cold water and making it warm constantly so that it makes a turbine move.

westurner 2y ago
To rephrase the question: what is the limit to the duration of sustained inertial confinement fusion plasma in the EAST, WEST, and ITER tokamaks, and why is the limit that amount of time? Don't those materials melt if exposed to temperatures hotter than the sun for sufficient or excessive periods of time? For what sustained plasma duration will EAST, WEST, and ITER need to be redesigned? 1 hour, 24 hours?
- Y_Y 2y ago
  EAST, WEST, URNER
  - westurner 2y ago
    [LLNL] "US scientists achieve net energy gain for second time in nuclear fusion reaction" (2023-08) https://www.theguardian.com/environment/2023/aug/06/us-scientists-achieve-net-energy-gain-second-time-fusion-reaction https://www.theguardian.com/environment/2023/aug/06/us-scien... But IDK if they've seen recent thing about water 100X'ing proton laser plasma beams from SLAC published this year/month; From https://news.ycombinator.com/item?id=43088886 https://news.ycombinator.com/item?id=43088886 : > "Innovative target design leads to surprising discovery in laser-plasma acceleration" (2025-02) https://phys.org/news/2025-02-discovery-laser-plasma.html https://phys.org/news/2025-02-discovery-laser-plasma.html >> Compared to similar experiments with solid targets, the water sheet reduced the proton beam's divergence by an order of magnitude and increased the beam's efficiency by a factor of 100 "Stable laser-acceleration of high-flux proton beams with plasma collimation" (2025) https://www.nature.com/articles/s41467-025-56248-4 https://www.nature.com/articles/s41467-025-56248-4 Timeline of nuclear fusion: https://en.wikipedia.org/wiki/Timeline_of_nuclear_fusion https://en.wikipedia.org/wiki/Timeline_of_nuclear_fusion
    - adrian_b 2y ago
      That energy gain was only in the plasma, not in the entire system. The extremely low efficiency of the lasers used there for converting electrical energy into light energy (perhaps of the order of 1%) has not been considered in the computation of that "energy gain". Many other hidden energy sinks have also not been considered, like the energy required to produce deuterium and tritium, or the efficiencies of capturing the thermal energy released by the reaction and of converting it into electrical energy. It is likely that the energy gain in the plasma must be at least in the range 100 to 1000, in order to achieve an overall energy gain greater than 1.
- zitterbewegung 2y ago
  The magnets in the device make the plasma be in a doughnut like shape to prevent it from touching the rest and it has active cooling, the parts that are around the plasma are made out of tungsten to dissipate heat. The sustained plasma duration would have to be turned on for as long as a traditional power generation device like a fission reactor or an oil / coal power station.
metalman 2y ago
there is destroyed and then there is a smoking hole in the side of the planet:) but I think it fair to say, that after 22 min running, that there is no way that it can be turned back on later kind of thing, fairly sure its a pwhew!, lookatdat!, almost lost plasma containment.... keep in mind that they are trying to replicate the conditions found inside a star with some magnets and stuff, sure its ferociously engineered stuff but not at all like the stuff that could exist inside a star so all in all a rather audacious endevour, and I wish them luck with it
- zitterbewegung 2y ago
  The system is not breakeven and the plasma was contained for 22 minutes so the situation would be the plasma was contained until it ran out of fuel. It is made out of tungsten for heat dissipation, has active cooling, has magnetic confinement with superconductors to prevent the system from destroying itself. https://en.wikipedia.org/wiki/WEST_(formerly_Tore_Supra) https://en.wikipedia.org/wiki/WEST_(formerly_Tore_Supra)
  - westurner 2y ago
    Fusion energy gain factor: https://en.wikipedia.org/wiki/Fusion_energy_gain_factor https://en.wikipedia.org/wiki/Fusion_energy_gain_factor : > A fusion energy gain factor, usually expressed with the symbol Q, is the ratio of fusion power produced in a nuclear fusion reactor to the power required to maintain the plasma in steady state
westurner 2y ago
> all power sources rely on taking cold water and making it warm constantly so that it makes a turbine move. PV (photovoltaic), TPV (thermopohotovoltaic), and thin film and other solid-state thermoelectric (TE) approaches do not rely upon corrosive water turning a turbine. Turbine blades can be made of materials that are more resistant to corrosion. On turbine efficiency: "How the gas turbine conquered the electric power industry" https://news.ycombinator.com/context?id=38314774 https://news.ycombinator.com/context?id=38314774 It looks like the GE 7HA gas/hydrogen turbine is still the most efficient turbine? https://gasturbineworld.com/ge-7ha-03-gas-turbine/ https://gasturbineworld.com/ge-7ha-03-gas-turbine/ : > Higher efficiency: 43.3% in simple cycle and up to 64% in combined cycle, Steam turbines aren't as efficient as gas turbines FWIU. /? which nuclear reactors do not have a steam turbine: "How can nuclear reactors work without steam?" [in space] https://www.reddit.com/r/askscience/comments/7ojhr8/how_can_nuclear_reactors_work_without_steam/ https://www.reddit.com/r/askscience/comments/7ojhr8/how_can_... : > 5% efficient; you usually get less than 5% of the thermal energy converted into electricity (International space law prohibits putting nuclear reactors in space without specific international approval, which is considered for e.g. deep space probes like Voyager; though the sun is exempt.) Rankine cycle (steam) https://en.wikipedia.org/wiki/Rankine_cycle https://en.wikipedia.org/wiki/Rankine_cycle Thermoelectric effect: https://en.wikipedia.org/wiki/Thermoelectric_effect https://en.wikipedia.org/wiki/Thermoelectric_effect : > The term "thermoelectric effect" encompasses three separately identified effects: the Seebeck effect (temperature differences cause electromotive forces), the Peltier effect (thermocouples create temperature differences), and the Thomson effect (the Seebeck coefficient varies with temperature). "Thermophotovoltaic efficiency of 40%" https://www.nature.com/articles/s41586-022-04473-y https://www.nature.com/articles/s41586-022-04473-y Multi-junction PV cells are not limited by the Shockley–Queisser limit, but are limited by current production methods. Multi-junction solar cells: https://en.wikipedia.org/wiki/Multi-junction_solar_cell#Multi-junction_cells https://en.wikipedia.org/wiki/Multi-junction_solar_cell#Mult... Which existing thermoelectric or thermopohotovoltaic approaches work with nuclear fusion levels of heat (infrared)?
- westurner 2y ago
  > Multi-junction PV cells are not limited by the Shockley–Queisser limit, but are limited by current production methods. Such as multilayer nanolithography, which nanoimprint lithography 10Xs; https://arstechnica.com/reviews/2024/01/canon-plans-to-disrupt-chipmaking-with-low-cost-stamp-machine/ https://arstechnica.com/reviews/2024/01/canon-plans-to-disru... Perhaps multilayer junction PV and TPV cells could be cost-effectively manufactured with nanoimprint lithography.

westurner 2y ago

To rephrase the question: what is the limit to the duration of sustained inertial confinement fusion plasma in the EAST, WEST, and ITER tokamaks, and why is the limit that amount of time? Don't those materials melt if exposed to temperatures hotter than the sun for sufficient or excessive periods of time? For what sustained plasma duration will EAST, WEST, and ITER need to be redesigned? 1 hour, 24 hours?

Y_Y 2y ago
EAST, WEST, URNER
- westurner 2y ago
  [LLNL] "US scientists achieve net energy gain for second time in nuclear fusion reaction" (2023-08) https://www.theguardian.com/environment/2023/aug/06/us-scientists-achieve-net-energy-gain-second-time-fusion-reaction https://www.theguardian.com/environment/2023/aug/06/us-scien... But IDK if they've seen recent thing about water 100X'ing proton laser plasma beams from SLAC published this year/month; From https://news.ycombinator.com/item?id=43088886 https://news.ycombinator.com/item?id=43088886 : > "Innovative target design leads to surprising discovery in laser-plasma acceleration" (2025-02) https://phys.org/news/2025-02-discovery-laser-plasma.html https://phys.org/news/2025-02-discovery-laser-plasma.html >> Compared to similar experiments with solid targets, the water sheet reduced the proton beam's divergence by an order of magnitude and increased the beam's efficiency by a factor of 100 "Stable laser-acceleration of high-flux proton beams with plasma collimation" (2025) https://www.nature.com/articles/s41467-025-56248-4 https://www.nature.com/articles/s41467-025-56248-4 Timeline of nuclear fusion: https://en.wikipedia.org/wiki/Timeline_of_nuclear_fusion https://en.wikipedia.org/wiki/Timeline_of_nuclear_fusion
  - adrian_b 2y ago
    That energy gain was only in the plasma, not in the entire system. The extremely low efficiency of the lasers used there for converting electrical energy into light energy (perhaps of the order of 1%) has not been considered in the computation of that "energy gain". Many other hidden energy sinks have also not been considered, like the energy required to produce deuterium and tritium, or the efficiencies of capturing the thermal energy released by the reaction and of converting it into electrical energy. It is likely that the energy gain in the plasma must be at least in the range 100 to 1000, in order to achieve an overall energy gain greater than 1.
zitterbewegung 2y ago
The magnets in the device make the plasma be in a doughnut like shape to prevent it from touching the rest and it has active cooling, the parts that are around the plasma are made out of tungsten to dissipate heat. The sustained plasma duration would have to be turned on for as long as a traditional power generation device like a fission reactor or an oil / coal power station.

metalman 2y ago

there is destroyed and then there is a smoking hole in the side of the planet:) but I think it fair to say, that after 22 min running, that there is no way that it can be turned back on later kind of thing, fairly sure its a pwhew!, lookatdat!, almost lost plasma containment.... keep in mind that they are trying to replicate the conditions found inside a star with some magnets and stuff, sure its ferociously engineered stuff but not at all like the stuff that could exist inside a star so all in all a rather audacious endevour, and I wish them luck with it

zitterbewegung 2y ago
The system is not breakeven and the plasma was contained for 22 minutes so the situation would be the plasma was contained until it ran out of fuel. It is made out of tungsten for heat dissipation, has active cooling, has magnetic confinement with superconductors to prevent the system from destroying itself. https://en.wikipedia.org/wiki/WEST_(formerly_Tore_Supra) https://en.wikipedia.org/wiki/WEST_(formerly_Tore_Supra)
- westurner 2y ago
  Fusion energy gain factor: https://en.wikipedia.org/wiki/Fusion_energy_gain_factor https://en.wikipedia.org/wiki/Fusion_energy_gain_factor : > A fusion energy gain factor, usually expressed with the symbol Q, is the ratio of fusion power produced in a nuclear fusion reactor to the power required to maintain the plasma in steady state

westurner 2y ago

> all power sources rely on taking cold water and making it warm constantly so that it makes a turbine move. PV (photovoltaic), TPV (thermopohotovoltaic), and thin film and other solid-state thermoelectric (TE) approaches do not rely upon corrosive water turning a turbine. Turbine blades can be made of materials that are more resistant to corrosion. On turbine efficiency: "How the gas turbine conquered the electric power industry" https://news.ycombinator.com/context?id=38314774 https://news.ycombinator.com/context?id=38314774 It looks like the GE 7HA gas/hydrogen turbine is still the most efficient turbine? https://gasturbineworld.com/ge-7ha-03-gas-turbine/ https://gasturbineworld.com/ge-7ha-03-gas-turbine/ : > Higher efficiency: 43.3% in simple cycle and up to 64% in combined cycle, Steam turbines aren't as efficient as gas turbines FWIU. /? which nuclear reactors do not have a steam turbine: "How can nuclear reactors work without steam?" [in space] https://www.reddit.com/r/askscience/comments/7ojhr8/how_can_nuclear_reactors_work_without_steam/ https://www.reddit.com/r/askscience/comments/7ojhr8/how_can_... : > 5% efficient; you usually get less than 5% of the thermal energy converted into electricity (International space law prohibits putting nuclear reactors in space without specific international approval, which is considered for e.g. deep space probes like Voyager; though the sun is exempt.) Rankine cycle (steam) https://en.wikipedia.org/wiki/Rankine_cycle https://en.wikipedia.org/wiki/Rankine_cycle Thermoelectric effect: https://en.wikipedia.org/wiki/Thermoelectric_effect https://en.wikipedia.org/wiki/Thermoelectric_effect : > The term "thermoelectric effect" encompasses three separately identified effects: the Seebeck effect (temperature differences cause electromotive forces), the Peltier effect (thermocouples create temperature differences), and the Thomson effect (the Seebeck coefficient varies with temperature). "Thermophotovoltaic efficiency of 40%" https://www.nature.com/articles/s41586-022-04473-y https://www.nature.com/articles/s41586-022-04473-y Multi-junction PV cells are not limited by the Shockley–Queisser limit, but are limited by current production methods. Multi-junction solar cells: https://en.wikipedia.org/wiki/Multi-junction_solar_cell#Multi-junction_cells https://en.wikipedia.org/wiki/Multi-junction_solar_cell#Mult... Which existing thermoelectric or thermopohotovoltaic approaches work with nuclear fusion levels of heat (infrared)?

westurner 2y ago
> Multi-junction PV cells are not limited by the Shockley–Queisser limit, but are limited by current production methods. Such as multilayer nanolithography, which nanoimprint lithography 10Xs; https://arstechnica.com/reviews/2024/01/canon-plans-to-disrupt-chipmaking-with-low-cost-stamp-machine/ https://arstechnica.com/reviews/2024/01/canon-plans-to-disru... Perhaps multilayer junction PV and TPV cells could be cost-effectively manufactured with nanoimprint lithography.